+1 on preventing stuff from falling into the engine.
Murphy's Law: Whatever bad thing that can happen, will happen. Protect yourself when ever you start working on stuff with two cheap tools.
1. A magnetic parts retriever on a flex stick.
2. A grabing parts retriever on a flex stick. These typically have spring loaded prongs to grab non magnetic parts and a push button to expand the prongs.
3. (Bonus number) Wad of tape with sticky side out on whatever thing is needed to reach wherever you need to reach.
These things should be in everyone's tool kit.